<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .box{
            width: 300px;
            height: 300px;
            border: 2px solid grey;
            margin: 100px auto;
            padding: 30px 50px 0 50px;
            box-sizing: border-box;
        }
        .input{            
            display: block;
            width: 200px;
            height: 30px;
            margin: 10px auto;
        }
        .button{
            width: 50px;
            height: 20px;
        }
    </style>
</head>
<body>
    <div class="box">
        <form action="http://www.jd.com" method="GET">
        <input type="text" placeholder="请输入用户名" class="input">
        <input type="password" placeholder="请输入密码" class="input">
        <input type="submit" class="button">
        <input type="reset" class="button">        
    </form>
    </div>
</body>
</html>